Repeater system



Feb. 22, 1944. e. KINER 2,342,586

' I REPEATER SYSTEM Filed May 5, 1941 5 Sheets-Sheet 1 Feb. 22, 1944.

E PLUG 55/17 G. KINER REPEATER SYSTEM Filed May 5, 1941 REPEA TE? OP/P.SET

3 sheets-sheet 2 EZEZZZ'Z ngr.

Feb. 22, 1944. G, lNER 2,342,586

REPEATER SYSTEM Patented Feb. 22, 1944 REPEATER SYSTEM Glenn Kiner,Markham, BL,

Switchboard and Supply Ill., acorporation oi. Illinois assignor toKellogg Company, Chicago,

Application May 5, 1941, Serial No. 391,822

This invention relates in general to telephone systems and moreparticularly to a voice current repeater system for th interconnectionof long distance lines.

One object of this invention is to provide for the more efllcient andeconomical use of voice current repeaters. Specifically the object is toprovide means whereby a voice current repeater which is common to agroup of link circuits may. if idle, be automatically included in anyone 01' the several link circuits incident to the normal use of thelatter, which link circuits may be located at one or different operatorspositions; and the further provision of means operative while the saidrepeater is in use to render it temporarily individual to such linkcircuit. A further object is to provide a repeater available to severalcords which while in use will provide secret service on the connection,but which when released from use, is automatically interposed intoanother corresponding busy cord connection. I

One feature of the invention is the provision of guard signals which areoperated at the several positions where the cords are located when therepeater is cut into a toll connection by one operator, to warn theoperators at other positions that the common repeater is already in use.

The foregoing features, and others not specifically pointed out, will bebetter understood from the following description taken in connectionwith the accompanying drawings wherein Fig. 1 illustrates a circuitarrangement of a repeater ton line circuit of this invention;

Fig. 2 shows a repeater cord circuit having two connecting cords;

Fig, 3 shows another repeater toll line circuit; and I Fig. 4 showsschematically the application of the invention to three positions, withmost of the cord circuit omitted.

General operation between lines. The toll line circuit also includes aringing relay RI which, when operated by the actuation of the ringingkey RK, connects ringing current from a suitable ringing current sourceRC, to the lines of station A to call the latter. v

9 Claims. (01. 179-41 Whepf'station A is calling, a ring-up relay RR isoperated by the ringing current and operates the line relay LR. The linerelay, in turn, closes a circuit to actuate the line signal LL, and lockup. A supervisory relay SR controls the signal LL to give the operator adisconnect or recall signal. 'A connecting relay CR is provided whichcontrols the efiacement of the line lamp signal LL, completes thecontinuity of the tip and ring con ductors T and R, and also connectsthe attenuation control pad GC, and the artificial line AL of thebalance network BN into the circuit.

, In Fig. 2, a repeater cord circuit is illustrated having a commontwo-way voice curent repeater VCR, and at least two cords T0 and T0 atthe same or different toll operators positions. The

SC. Guard lamps GL and GL' oi the cords give visual indication to theoperators when the twoway vo'ice current repeater VCR having theterminals L, L', L and L L, L is being used in a connection between acalling and 9. called toll line. The voice current repeaters and therepeater line circuits, may be of any well-known type as, for example,those shown in U. S. Patent No, 2,050,292, issued to George R. Eaton.Listening keys LR and LK', associated with the respective cords, whenactuated, connect the operators sets to the cord conductors, and removeground from the circuit of the respective repeater connecting relays. v

In Fig. 3, is shown another repeater line circuit RL', for the calledtoll substation B, extending through repeating coil RC to a tollposition at an exchange and terminates in a local jack LJ', and arepeater jack TJ'. This line circuit is similar to that in Fig. 1.Further description is not believed necessary. Like apparatus in thetwo'flgures are indicated by corresponding reference characters.

Detail operation Having described, in general, the apparatus of thisinvention, a more detailed description of operation will now be given bytracing the operation of the circuits in establishing a connectionbetween a calling toll substation A and a called toll substation B.

The subscriber at the toll substation A, initiates a call by operatingthe hand generator MG and ringing current therefrom flows through therepeating coil RC of the line circuit to temporarily operate the ring-uprelay RR. The

closing of the front contact by armature 2 of this relay completes anoperating circuit for line relay LR. The line relay circuit extends fromgrounded battery through the winding of relay LR, back contact andarmature 3 of connecting relay CR, conductor 4, to ground at frontcontact and armature 2 of relay RR. Upon the termination of ringingcurrent, relay RR restores and opens the energizing circuit of the linerelay. In restoring, its armature 2 completes a circuit for the linesignal LL through armature I and front contact of the line relay LR, andover conductors 9 and 8. The line relay LR operates and looks throughits front contact and armature over conductor 6, to ground through backcontact and armature 1 of the relay CR.

The line lamp LL is lighted at toll position C in the exchange, and thetoll operator noting the display on indicator LL, inserts an answeringplug of an ordinary cord (not shown) into the calling line local jackLJ. Upon being informed that the called party is located at the tollsubstation B, the operator withdraws the plug from the local jack LJ andinserts the answering plug AP of a repeater cord circuit TO into therepeater jack TJ. The insertion of the plug AP into the jack TJ closesthe normally open contact ll of the latter which completes a circuit forthe connect relay CR over conductors l2 and I3. The operation of relayCR moves its armature 3 to break the locking circuit of line relay LR,and prepares a circuit for relay SR. The line relay restores itsarmature l0 and eflaces the line signal LL.

The operator may now actuate the listening key LK to connect theoperators set to the tip and ring conductors T and R of the cord TO andconverse with the subscriber at A. The closure of front contact andarmature l4 and the closure of front contact and armature l5 of relay CRcompleted the continuity of the tip and ring conductors T and R. RelayCR also connects the gain control pad GC and the balance network BN intothe circuit. Assuming that the wanted party is the toll subscriber atthe substation E (Fig. 3), the operator now releases listening key LKand inserts the calling plug CP of repeater cord circuit TO into therepeater jack TJ' of the called line.

The plug seat switch PS (associated with the calling plug CP) isoperated by removal of the plug from its seat and permits the normallyopen spring contact Hi to close and establish a circuit for the repeaterswitching control relay SC, from battery through its own winding,conductor l'l, back contact and armature l8 of the repeater switchingcontrol relay SC (of the cord circuit T0 at position D), conductors l9and I8, to ground at closed contact l6 of the plug switch. Relay SCoperates and locks through its front contact and armature 20, overconductor Hi, to ground at the closed contact l6 of the plug switch PS.The circuits of the repeater connecting relays RP and RP are in paralleland traced from battery through their respective windings, conductors 22and 23, front contact and armature 2| of the relay SC, conductor 24,

to ground at normally closed contact 28 of the operators listening keyLK. The relays RP and RP operate. The closing by armatures 26, 21 and 28of the front contacts of relay RP connects the tip, ring, and sleeveconductors T, R, and S of the answering end of the cord or link circuitTO by way of conductors 29, 30, 3|; and 32, 33, and 34 to the repeaterterminals L, L, and L The closing by armatures 3T, 38, and 39 of thefront contacts of relay RP, (associated with the calling end of the cordTO) connects the respective tip, ring, and sleeve conductors T, R, and Sat the calling end of the cord TO over conductors 40, ll, 42; and 43,44, and 45 to the terminals L L and L at the other side of the voicecurrent repeater.

The insertion of the calling plug CP into the trunk jack TJ' of therepeater line circuit RL', (Fig. 3) closes an energizing circuit for theconnect relay CR which operates from battery through its own winding,conductors l3 and I2, to ground at the now-closed contact H of the jackTJ'. The closing of front contacts on relay CR, by armatures I4, l5 and54, connects the attenuation control pad GC' and the balance network BN'into the talking circuit of the repeater line of station B. The closingby armatures 3' of front contact on relay CR prepares a circuit for thesupervisory relay SR which will be operated, when a disconnect or recallsignal is received from the called toll line B.

The operator now signals the called station B by operating the ringingkey RK associated with the line circuit RL'. The closing of its normallyopen contact completes a circuit for the ringing relay RI. Ringingcurrent from ringing source RG' flows through front contact and armature58 of relay RI, normal contact 59 of the local jack LJ', windings and Biof the repeating 0011 RC, normal contact 62 of the local jack, to groundat front contact and armature 63 of the relay RI. Ringing currentinduced in the windings 64 and 65 of the repeating coil RC actuates thesignal at the called substation B. The operator may monitor the call inthe usual manner. The talking circuit, when the subscriber at B answers,is traced over the T and R conductors which include the connected voicecurrent repeater.

Upon conclusion of conversation, the subscriber at the calling tollsubstation A restores the receiver and actuates the hand generator MG toagain operate the ring-up relay RR of the line circuit RL. The closingof its front contact by armature 2 of relay RR completes a circuit forthe supervisory relay SR through front contact.

and armature 3 of relay CR. The relay SR operates and locks from batterythrough its own winding, its front contact and armature B8, to ground atfront contact and armature I of relay CR. At the conclusion of signalcurrent, relay RR restores, closing at its back contact by armature 2 acircuit for the combined disconnect and line signal means LL, frombattery through LL, conductor 8, front contact and armature 10 of relaySR, back contact andarmature H! of relay LR, to ground at back contactand armature 2 of relay RR. The signal LL indicates that conversation isterminated.

The party at the called toll substation B, upon completion ofconversation, operates hand generator MG to actuate the ring-up relay RRof the repeater line circuit RL'. The closing of its front contact byarmature 2 closes the circuit for the supervisory relay SR from batterythrough winding oi relay SR front contact and armature 3' of relay CR,conductor 4, to ground at front contact and armature 2 of relay RR.Relay SR operates. and locks through its front contact and armature 68,to ground, at front contact and armature 1 of relay CR. The cessation ofringing current from the toll substation B releases relay RR whichrestores, and again closes its back contact by armature 2'. It thereuponlights the disconnect signal LL of the line circuit RL, from batterythrough the lamp LL, conductors 8 and 9, front contact and armature 10of relay SR, back contact and armature l of relay LR, to ground, at backcontact and restored armature 2 of the relay RR.

The operator noting the disconnect signals LL and LL, removes the plugsAP and CP from the respective jacks TJ and TJ'. The restoration of theplug CP upon its plug switch PS again opens contact l6 to interrupt thelocking circuit of the relay SC of the cord TO. Relay SC restores andreleases armature 2| from its front contact which restores relays RP andRP. The opening of armatures 2'6, 21, and 28 from their front contacts,and armatures 31, 38, and 39 from the front contacts of the respectiverelays RP and RP, disconnects the two-way voice current repeater fromthe cord TO and permits its use for establishing other repeaterconnections.

Whenever the repeater is in use, suitable guard lamps GL and GL warn theoperators that it is not available for use. The energization, as beforedescribed, of the repeater switching control relay SC of the tolloperator's cord TO, closed its front contact by armature 50 andconnected ground to the guard lamp circuit.

Assuming now, however, that the toll operator at the position D ignoresthe lighted lamp GL vat her position and attempts to establish aconnection with the repeater, the removal of the calling plug CP fromits plug seat brings about the closing of the normally open contact l6of plug switch PS, but this ground does not complete an energizingcircuit for the relay SC (of the cord T0 of the toll position D) becausethe initial energizing circuit of this relay is interrupted at the backcontact and armature 8| of the relay SC (of the cord 'IO-at the positionC). Relay SC does not operate and front contact and armature 2| remainopen. Relays RP and Pt of the cord TC consequently cannot operate toclose the circuits to the respective repeater terminals L, L, L, and L LL The cord, however, at this time may be used to complete a non-repeatertype connection if traffic requires its use even though the repeater isnot immediately available. In such a case, the connection is directlythrough the T, R, and S conductors of the cord. The operation of plugswitch |6, however, prepared a circuit for the repeater switching relaySC so that if the repeater is released at position C, upon terminationof a call thereat, it will be automatically connected into the cordcircuit at position D to improve the conversational characteristics ofthe latter circuit, provided, of course, that the connection iscontinuing. As soon as armature 8| closes its back contact, the circuitof relay SC is completed. It then operates and in turn completes thecircuits of relays RP and RP These relays au tomatically connect therepeater to the circuit at their front contacts by respective armatures26', 21 and 28', and also arrna-tures 31, 38, and 39'.

Now, if the operator at the toll position D had established the firstconnection, i. e., between the calling toll substation A and the calledtoll substation B, then the energizing circuit of relay SC (of the cordTO) extended from battery through the winding of relay SC, conductor 82,back contact and armature 8| of relay SC (of cord CO at position C),conductors 83 and 84, to ground at the closed contact l6 of the actuatedplug switch PS. Relay SC would operate and'lock to ground at closed plugswitch contact l6, by armature 28 engaging its front contact. Relay SCalso completes energizing circuits for the relays RP and RP from theground at back contact and armature of the operators key LK, The closingby armatures 26, 21, and 28 of front contacts of relay RP and byarmatures 31, 38", 38 of front contacts of relay RP connects the tip,ring. and sleeve conductors of the cord TO to the respective terminalsL, L, L and L L L of the repeater via conductors 29', 30, 3|, 32, 33, 34and conductors 40, 4|, 42, 43, 44, 45. The closing of front contact byarmature 80 of relay SC completes the multiple circuit of the guardlamps GL and GL for the toll positions C and D.

Now, if the toll operator at position C, at-

I tempts to make a connection which would include the repeater, anon-repeater type toll cord connection may be established, but therepeater cannot beincluded in the circuit. The initial energizingcircuit of relay SC of the cord T0) is held open at back contact l8 cfenergized relay SC. Hence. relay SC cannot operate and its open frontcontact and armature 2| prevents the energizing of relays RP and RP.Relays RP and RP remain normal, thus a second toll operator cannotintrude on the established connection. It is, therefore, seen thatalthough the common repeater is available to a group of at least twotoll operators cords for connection in the toll cord circuits. when aconnection has been made by the calling plug at one position, all othercords of the common group are precluded from either using the repeateror interfering with its use in an existing connection.

In Fig. 4, a schematic wiring diagram shows the adaptation of theinvention to three cords having a repeater circuit common thereto. Ofcourse, each of the positions may have additional cord circuits, havinga common repeater avail able for connection. Although each repeater canonly be used in only one cord connection at a time, it may automaticallybe placed in another busy cord. when released from a prior connection.

Where more than two cords are common to a repeater, additional contactsare needed on the SC relays, so that the energizing circuit of eachrelay is under the control of contacts on each of the others of thecommon group of cord circuits. For example, relay SC in Fig. 4 has itsenergizing circuit extending through back contact and armature 98 ofrelay SC"; back contact and armature of relay SC; and conductor I9; toground through normally open contact I6 of plug switch E. Similarly.relay SC has its winding in series with back contact and armature 9| ofrelay SC; back contact and armature 9| of relay SC; conductor l9,normally open contact I5 of relay switch F, to ground. Relay SC has itswinding in the circuit of back contact and armature 9| of relay SC; backcontact and armature 90 of relay SC; conductor IE", to ground throughnormally open contact l6" of plug switch G. The operation of the cordcircuit in other respects is the same as previously described.

at any one of the positions, or two of the re-' peaters could beemployed with two cords at one position and the other repeater with acord at either of the other positions. In other words, the repeaters maybe used at whichever positions the varying traillc requirements dictate.

A system of the type herein described is useful for private telephonesystems such as used by oil companies, railroads, etc, where the normaltrafilc does not warrant the cost of many'ex pensive repeaters, butwhere occasional emergency traflic conditions may warrant conversationalconnections omitting a repeater; or at least temporarily omitting therepeater for a part of a conversation.

Although a preferred embodiment ofthis invention is illustrated anddescribed, variations in the details are contemplated and the inventionshould be limited only by the scope of the appended claims.

What is claimed is:

1. In a telephone system, a repeater circuit comprising a voice currentrepeater, two or more cords arranged to separately include said repeaterserially in their respective circuits, and relay means actuated bysetting up a connection with one of said cords to seize said repeater,if idle, and connect it into the used cord, and means to preventdisturbing the connection by the use of another of said cords.

2. In a telephone system, a plurality of connecting links, a two-wayrepeater, means for connecting said repeater, if idle, to any one ofsaid links taken for use, means permitting the use of asecond one ofsaid links in establishing a connection exclusive of said repeater, andmeans for automatically connecting said repeater to said second one ofsaid links incident to disestablishing the connection through thefirst-mentioned link.

3. A telephone system including two or more cords, a voice currentrepeater common to said cords and adapted to be connected in any one ofsaid cords one at a time, a switching control relay for each cord, aplug seat switch at the calling end of each cord, an energizing circuitfor each control relay extending through the plug switch of itsrespective cord and through normal contacts on the control relays of allother of said cords, repeater connecting relays for each cord arrangedto connect said repeater therein, the operation of each control relaybeing arranged to energize the repeater connecting relays 01 its cord,to lock itself through said plug switch, and to open the energizingcircuit of the control relays of each of the other cords.

4. In a telephone system, a plurality of connectin links, a two-wayrepeater arranged for use individually with any of said links, means forautomatically including said repeater in the first established linkconnection and to render said repeater individual to said connectionduring the continuance thereof, means whereby other links may beemployed to establish connections, exclusive of said repeater, duringthe continuance of the connection first established, and

' 5 means whereby. upon the termination of a connection in which saidrepeater is included, said repeater will be automatically transferredinto another one of said existing connections one at a time, so long asany of said links continue in use.

5. In a telephone system, a plurality of links, a two-way repeatercommon to said links, means for automatically including said repeater ina link connection and for rendering it individual 5 to said connection,means' for establishing nonrepeater type connections through any or allof the other links, and means to automatically transfer said repeaterfrom a terminatedlink connection to another continuing link connectionuntil all of the link connections have been terminated.

6. In a telephone system, links, switching means enabling talkingconnections to be set up through said links respectively, a voicecurrent repeater common to said links, the terminal con- 5 ductors ofsaid repeater being multipled to open contacts at each of said links,relaymeans in each link operable incidental to the setting up of aconnection therethrough for splitting the link and for closing said opencontacts to insert said repeater into the link, and interlocking circuitconnections between the relay means of the links effective to preventthe insertion of said repeater into more than one link at a time.

7. In a telephone system, links, switching means enabling talkingconnections to be setup through said links respectively, a. voicecurrent repeater common to said links, the terminal conductors of saidrepeater being multipled to open contacts at each of said links, andmeans in each 0 link operable incidental to the setting up of aconnection therethrough for splitting the link and for closing said opencontacts to insert said repeater into the link.

8. Ina telephone system, links, switching means enabling talkingconnections to be set up through said links respectively, a, voicecurrent repeater common to said links, the terminal conductors of saidrepeater being multipled to open contacts at each of said links, andmeans in each link for splitting the link and for closing said Opencontacts to insert said repeater into the link, whereby the repeater maybe used in a connection set up through any one of said links.

9. In a telephone system, links, switching means GLENN KINER.

enabling talking connections to bet set up through

